Hereīs my problem. I bought a while ago a hometheatre kit with a powered subwoofer in a country near mine (Iīm Brazilian). Well, it stopped working and no technician was able to fix it. Itīs brand, FOSTON, is unknown, and no spare parts can be found here in Brazil. I bought later a Pioneer receiver (VSX-812) and plugged all the other speakers in it (center, left, right and surround ones), but I canīt plug my subwoofer because itīs gone. So, as itīs speaker is working, Iīd like to plug it as a passive one in my receiver, but I donīt know how to do the modifications to it. I want to throw away the amplifier and use itīs box and speaker as a passive one because I donīt want to spend more money!!! Is it possible? I coudnīt find information in the internet...

Assuming that your receiver does not have a power section for a sub you'll have to buy or build a passive crossover to use the sub wired parallel with your mains. It is not an inexpensive proposition in the event that you want to use high quality components; in fact, for the price of a top quailty passive crossover for a sub you can buy a new amp for it instead.

I did a search for a Pioneer VSX-812. All I found was the latest model, the VSX-D812. Since features get added with each model change, the "D" model probably has all the features your model does, plus some more.

This is what Pioneer lists for it's own secification on the VSX D812 model-probably sightly higher up the scale than your 812 model.

"This jack sends a preamplified signal to a subwoofer for amplification. This method provides the subwoofer with a pure signal, and that's the foundation of good sound."

So there is no amplified power to send to a subwoofer in the D812 model, and almost certainly not in your older model.

Either yiou have to do what Bill said, or find an old amp or receiver and run the subwoofer off that. Complicated and probably unsightly.

I don't know if you can use the rear channels for a sub-some systems cut off bass signals going to the rears.

Unless you are willing to take a chance running the sub in parallel with your main speakers, or are willing to go the separate amp route, I would find another sub.

Parts Express in America has some models that are under $100, but I don't know the tax and import situation. However, I believe there are only one or two firms in Asia that make virtually all of these subwoofer amps for all the manufacturers of mid-fi equipment, so you might be able to locate a Brazilian supplier.

I think you are going to end up buying a new powered subwoofer, when all things are considered. However, good luck.

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Well, actually my receiver has a powered subwoofer output, in which is written "PRE-OUT" which looks like an RCA terminal, and a "passive subwoofer or single surround back speaker" configuration, which has banana like terminals (one for + and one for - ). So, could I then plug both wires from my subwoofer speaker directly in this "passive subwoofer output ? With no extra components? In my receiver manual it says it has enough power to run everything with no extra amplifiers. Would the sound for this now passive subwoofer be with the same quality of a powered one ? I donīt need super loud sounds, my living room is not big and I plan to watch DVDs and play games in my XBOX.

I believe you will be able to use your receiver in the passive subwoofer mode. I will be able to confirm this for you on Monday when I get the chance to check the instruction manuals.
It will not give you optimum subwoofer performance since the active subwoofer probably had built in EQ to correct the response of it's driver in that box.
However you will at least have some bass sounds!! and it won't cost you.